CCN4 and Nephroblastoma: The CCN family, an important component of the secretory ECM-related protein family, consists of six family members, Cyr61/CCN1 (cysteine-rich 61), CTGF/CCN2 (connective tissue growth factor), Nov/CCN3 (nephroblastoma overexpressed), and Wnt pathway proteins (WISP1/CCN4, WISP2/CCN5, and WISP3/CCN6) (Jun and Lau, 2011).